When you a make a template with the template builder you have to make sure to add elements to it. So when you click on Frontpage or your “dynamic” template that you made it should have items in it like Page Content or any of the others available.

Then when you add that template to a page, that page will use the “template” layout. If that template doesn’t actually show the slideshow or page/content then it will completely ignore everything you add in the visual editor or to the gallery (where you added that single image).